Methods	4-armed randomised controlled trial which aimed to improve the uptake of prenatal care and pregnancy outcomes (especially low birthweight), and included advice about smoking Study conducted in a semi-rural county of New York State (USA), with recruitment between April 1978 and September 1980
Participants	Inclusion criteria: Pregnant women with no prior live births + any of the following: < 19 years; single; low socio-economic status, and any other women with no prior live births who wished to participate in the program Exclusion criteria: > 25 weeks’ gestation (though some were enrolled at 25-29 weeks) Recruitment: Through private obstetricians’ offices, planned parenthood, public schools health department antenatal clinics and other health and human service agencies. 10% of target population entered prenatal care too late, 10% were not referred from private care. 500 women were interviewed and 400 enrolled (80%). Families were stratified by marital status, race, and 7 geographic regions (C = 90, I1 = 94, I2 = 100, I3 = 116). 141 smokers (C = 64, I = 77). Baseline characteristics: Mean cigarettes per day at intake: C = 6.94, I = 7.65. 47% < 19 years old, 62% single, 61% low SES (15% had none of these factors). Non-Whites (46) excluded because too few; serious maternal or fetal conditions (20) excluded Progress+ coding: Low SES.
Interventions	Control: Health and developmental screening of the baby at 12 and 24 months; Intervention 1: Control + free transport to pregnancy and well-child visits (control); Intervention 2: 1+ nurse home visits during pregnancy (intervention); Intervention 3: 2+ nurse home visits in child’s first 2 years. The focus of the home visiting was individualised from a detailed curriculum dealing with information on fetal and infant development; improvement of maternal diet; monitoring weight gain; elimination of cigarettes, alcohol and drugs; identifying pregnancy complications; encouraging rest, exercise and hygiene; preparing for labour birth and early newborn care. The intervention was also described as enhancement of informal support systems (partners, family and friends) and linkage of parents to community services, including nutritional care, prenatal providers and other services Main intervention strategy: Social support (tailored intervention) compared to usual care. Intervention 2&3 (nurse-visiting arms) compared to control and intervention 1 arms (no nurse visiting) in this review. Intensity: Freqency (C = 0, I = 6), Duration (C = 0, I = 4). Usual care intensity: F = 0, D=0 Intervention provided by dedicated study team: Efficacy study
Outcomes	Cotinine levels taken in a subsample (n = 116), but no women reported smoking cessation at 32 weeks’ gestation (late pregnancy)*. Mean cigarettes per day at 32 weeks (late pregnancy*). No mean cotinine levels reported for inclusion. Self-reported reduction in cigarettes, but not reported as a mean for inclusion in this review. Birth outcomes were not included as aspects of the intervention, other than smoking cessation, may potentially improve birth outcomes
Notes	SDs for mean cigarettes per day were not reported, therefore we calculated a mean SD from 14 studies with available mean cigarette SDs (6.5) to include in this review, as recommended by the cochrane handbook
Risk of bias
Bias	Authors’ judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information provided.
Allocation concealment (selection bias)	Unclear risk	Not specified.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	6.5% attrition (C = 12, I = 14) due to moving or miscarriage. However outcomes for 307/400 women only reported. Outcomes for all smokers at intake reported
Selective reporting (reporting bias)	Low risk	Detailed range of outcomes reported.
Other bias	Unclear risk	No other bias detected.
Biochemical validation of smoking abstinence (detection bias)	Low risk	Serum cotinine analysis on subsample of 116. No self-reported cessation to validate
Blinding of participants and personnel (performance bias) All outcomes	High risk	Home visitation programme. Blinding of participants and personnel not viable
Blinding of outcome assessment (detection bias) All outcomes	Low risk	The interviewers and medical record reviewers hired by the research project did not know to which treatment the women had been assigned
Incomplete implementation	Unclear risk	Not reported.
Equal baseline characteristics in study arms	High risk	Women assigned a nurse had less social support.
Contamination of control group	Low risk	Home visits.